Jack wrote:

However, as we are well aware, an operating engine is not necessary to
continue controlled flight. So the question remains: why was it
necessary to use the parachute? Was the terrain unlandable, or was the
pilot more conscious of the parachute's capabilities than the aircraft's?

This is what worries me about ballistic parachutes: they turn a
possible crash into a guaranteed one. He doesn't seem to have spent any
time at all trying to work out whether his plane was flyable, and
although he walked away from the crash in an orchard, he mightt have
been so lucky. One you've pulled the handle you have no choice about
where you land ... Railway line? Road? Electricity substation? Market
place?

Ian